ch17.008_prob

Perl Best Practices the source code

##############################################################################
## Code fragment (NOT RECOMMENDED) from Chapter 17 of "Perl Best Practices" ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;


package Process::Queue;
use Carp;
{
    use overload (
        # Type coercions don't make sense for process queues...
        q{""}   => sub {
            croak q{Can't stringify a Process::Queue};
        },
        q{0+}   => sub { 
            croak q{Can't numerify a Process::Queue };
        },
        q{bool} => sub { 
            croak q{Can't get the boolean value of a Process::Queue };
        },
    );
}
 
# and later...
 
package Socket;
use Carp;
{
    use overload (
        # Type coercions don't make sense for sockets...
        q{""}   => sub {
            croak q{Can't convert a Socket to a string};
        },
        q{0+}   => sub { 
            croak q{Can't convert a Socket to a number};
        },
        q{bool} => sub { 
            croak q{Can't get the boolean value of a Socket };
        },
    );
}